Sleep quality among undergraduate medical students in Rwanda: a comparative study

Despite the abundance of literature highlighting poor sleep quality among medical students and its detrimental impact on their mental well-being and academic performance, no study has been conducted to investigate the sleep quality of undergraduate medical students in Rwanda to date. Therefore, this study sought to determine the magnitude of sleep quality of undergraduate medical students in Rwanda and to compare the scores of seven components of sleep quality across classes. This cross-sectional study was conducted among 290 undergraduate medical students aged 18–35 years (mean = 24, SD = 2.9) randomly recruited countrywide from 1st November 2021 to 1st March 2022. The questionnaire was self-administered with 2 sections: characteristics of medical students, and Pittsburgh Sleep Quality Index (PSQI). The Pearson Chi-square test was used to test whether the categories of seven components of sleep quality differ between classes, then ANOVA followed by the post hoc test was used to test if the seven components and global score of Pittsburgh Sleep Quality Index differ between classes. The results revealed that the global PSQI mean score was 7.73 (SD = 2.83), with fifth-year medical students reporting the highest PSQI mean score (M = 8.44, SD = 2.77), followed by first-year (M = 8.15, SD = 3.31). One-way ANOVA showed that the global PSQI score (F = 2.76, p = 0.028), subjective sleep quality (F = 3.35, p = 0.011), habitual sleep efficiency (F = 10.20, p < 0.001), and daytime dysfunction (F = 3.60, p = 0.007) were significantly different across classes. Notably, the post hoc test revealed significant scores differences in the global PSQI score between class II and V (p = 0.026), in subjective sleep quality between class I and II (p = 0.043), and between class I and IV (p = 0.016); habitual sleep efficiency between class V and all other classes (p < 0.001); and daytime dysfunction between class III and IV (p = 0.023). This paper concludes by arguing that poor sleep quality is highly prevalent among medical students in Rwanda, with final and first-year students reporting the poorest sleep quality. There were significant differences across classes in the global PSQI, subjective sleep quality, habitual sleep efficiency, and daytime dysfunction. Intervention approaches such as sleep education, behavioral changes, and relaxing techniques are recommended to address contributing factors and ultimately maximize the academic goals of Rwandan medical students.

Study population and settings. Rwanda is a Sub-Saharan African country located in the East Africa, covering a land area of 26,338 km 2 . The country is divided into four provinces (East, West, South, and North), as well as the capital city, Kigali. It is the country that has three Higher Learning Institutions including the University of Rwanda (UR); the Institute of Legal Practice and Development (ILPD), Rwanda's dedicated postgraduate institution for legal education; and Rwanda Polytechnic (RP). Regarding medical programs, it has 3 medical schools including one for a public institution found at the University of Rwanda and 2 from private institutions: the University of Global Health Equity (UGHE) and the Adventist University of central Africa (AUCA). Rwandan medical school began at the former National University of Rwanda, which is now part of the University of Rwanda, College of Medicine and Health Sciences, School of Medicine, and Pharmacy. It is the largest medical school to date, offering both undergraduate and postgraduate programs. It has three campuses including the REMERA campus located in Kigali city, HUYE campus located in the southern province, and the GAKO campus located in the Eastern province.
Sample size and sampling technique. A list of registered medical students for the academic year 2021-2022 was obtained from the Deans of the School of Medicine at each university. The total number of students was 1062, with 960 from UR, 66 from UGHE, and 36 from AUCA. The sample size was calculated using Yamane formula: nY = N 1+Ne 2 , where "N" stands for 'population size' , and "e" for Alpha level (e = 0.05) at the confidence interval of 95%. nY = www.nature.com/scientificreports/ Data collection and measurements. Data were collected by trained data collectors from November 1st, 2021, to March 1st, 2022. All medical students enrolled at one of the three universities were included in the study. However, medical students under 18 years of age were not included as a tool used in this study to assess the sleep quality of medical students is designed for adults 22,26 . Moreover, as in previous studies, medical students with a chronic medical condition were excluded 27 . A chronic medical condition was a self-reported presence of one of the following: non-communicable disease or bronchial asthma 27 . Twelve of the 302 medical students approached were excluded because six had asthma, one had bipolar disorder, and five refused to participate. The study employed a self-administered questionnaire consisting of two sections: characteristics of medical students and the Pittsburgh Sleep Quality Index (PSQI) as described below: Characteristics of medical students. The characteristics of medical students were gender, age in years, university, class, scholarship, clinical rotations, accommodation, living with a roommate, smoking habits, class attendance, studying in team, and self-reported academic score. www.nature.com/scientificreports/ were more prevalent among fourth-year students, whereby a total of 73 (60.8%) and 33 (27.5%) had mild and moderate sleep disturbances respectively. The use of sleeping medications was more prevalent among the firstyear students, 3 (11.5%) while sleep dysfunctions were more prevalent among third-year students 40 (91%). In general, poor sleep quality was more prevalent among first, and fifth-year medical students, 21    Significance of the seven components and the global score of Pittsburgh Sleep Quality Index between classes. As in our case, the data exhibit equal variance (as suggested by Lavene's Statistics), Post Hoc test was selected to determine which classes were significantly different from others. There were significant scores differences in subjective sleep quality between class I and II (p = 0.043) and between class I and IV (p = 0.016); habitual sleep efficiency between class V and all other classes (p < 0.001); daytime dysfunction between class III and IV (p = 0.023) and the PSQI global score between class II and V (p = 0.024) ( Table 4).

Discussion
This study evaluated the sleep quality of undergraduate medical students in Rwanda using the Pittsburgh Sleep Quality Index (PSQI) and compared the seven components and global score of Pittsburgh Sleep Quality Index across classes. We found a high prevalence of poor sleep quality, 80%, with a significant difference between classes where 86.2% and 80.8% of final and first-year students respectively had poor sleep quality. Our results replicate the findings of studies conducted in Kazakhstan and Brazil which respectively reported that 79.2% and 80.95% of medical students had poor sleep quality 4,30 . However, the current study's prevalence of poor sleep quality is comparatively higher than what has been reported in similar studies 8,14,22,31 . In Malaysia and Saudi Arabia, 44.23% and 63.2% of medical students reported poor sleep quality respectively 8,22 . In SSA countries like in Ethiopia and Nigeria, 55.8% and 32.5% medical students respectively had poor sleep quality 14,31 . The current study's poor sleep quality may be explained by the stress levels that medical students in Rwanda experience 32 , post-conflict situations 20 or the COVID-19 pandemic that heightened online learning 33,34 . like our study, research from North India found that first-year students reported having worse sleep quality 35 . The poorest sleep quality reported among final and first-year students may be justified by several clinical rotations that come with financial distress during this period for final-year students, and countless encountered challenges like new schedules, unfamiliar www.nature.com/scientificreports/ environments, and academic demands for first-year medical students 8,32 . Consistently, scholars revealed that last year's medical students encounter financial trouble that raises their stress levels 32 , in turn worsening their sleep quality 36 . Thus, actions must be taken among final-year students in Rwanda to address this grave problem since their poor sleep quality may jeopardize the lives of the patients they monitor during their clinical rotations. Similarly, first-year medical students need induction activities to promote their health for sleep hygiene. Despite the recommendation that sleep duration per night should be 7 h or above for younger adults 5,6 , our study participants slept 5.5 h per night (on average) with 87% sleeping fewer than 7 h. In congruence with our findings, studies conducted in Saudi Arabia, and Slovenia showed that medical students respectively slept 5.8 h and 5.84 h on average 18,37 . Moreover, our results were in line with the findings that 87.6% of medical students slept less than 7 h per night in Pakistan 1 . Worryingly, sleep less than 7 h is associated with poorer general health and increased risk or presence of disease 35 . It has been also studied that sleep deprivation among medical students leads to sleepiness during the daytime and contributes to medical errors, road traffic accidents, and a decrease in academic performance 15 . Regrettably, more than half (53.5%) in the current study had difficulties falling asleep, taking longer than 15 min. Comparatively, a higher proportion of medical students in Saudi Arabia (65.1%) and Brazil (72%), respectively, reported taking more than 15 min to fall asleep 38,39 . The predictors of sleep difficulties among Mexican medical students have been found as symptoms of stress, anger, worry, cognitive hyperarousal, and hypervigilance 40 . Similarly, medical students in Rwanda reported mild to moderate levels of stress 32 . Nevertheless, medical students still sacrifice their sleeping hours to study because of their excessive academic burden 12 . Therefore, open discussions between medical students and academic staff are needed to identify ways to alleviate potential causes that contribute to fewer hours of sleep among medical students in Rwanda.
Mild to moderate sleep disturbances were found among 84.5% of medical students in the current study. Comparatively, this rate is higher than the global prevalence of sleep disturbances (76.8%) in medical students 40 . These results are also higher compared to a study conducted at an Italian University revealing that 63% of medical students had symptoms of sleep disturbances 9 . However, the results from this study are lower than those shown in similar African studies in Ethiopia (95.1%) and Egypt (93.4%) 31,41 . Though the current study reported lower sleep disturbances compared to other African countries, the rate is still worrisome, and thus, it should be kept much lower because of the studied relationship between sleep disturbances, and academic performance 40 . According to some literature, issues of sleep disturbances are the possible markers of current and future psychiatric problems among medical students 40,42 . Further studies also documented that sleep disturbances among medical students not only put them at risk of psychiatric problems but also affect their cognitive skills, emotional intelligence, and academic performance 12 . The current study also revealed that daytime dysfunctions were at 73% with significant differences between classes, notably between class III and IV (p = 0.023), in which third-year students reported more daytime dysfunctions than others, 91%. The results of a significant difference in daytime dysfunctions between different classes agree with a study in Brazil that revealed similar findings 39 . However, the prevalence is higher compared to a study conducted in Jordan that found a prevalence of 50% 3 . Daytime sleep dysfunctions are known to cause medical errors and decrease academic performance 15 . In Rwanda, measures such as regular counseling and education to address daytime sleep dysfunctions among medical students are critical to prevent medical errors as well as improve their behaviors and lifestyle for better academic performance.
Despite a higher prevalence of poor sleep quality in the current study, 79% of medical students classified their subjective sleep quality from fairly to very good. However, their habitual sleep efficiency was found poor whereby 68% of medical students had less than 65% of habitual sleep efficiency. This component was found to be even the most impaired sleep component, which is contrary to an Iranian study which found that habitual sleep efficiency was the best sleep component 11 . Close to our findings, a study in Saudi Arabia reported that 76.1% of medical students classified their subjective sleep quality from fairly good to very good 38 . Also, in India, 74.7% reported their subjective sleep quality from fairly to very good 35 . Contrary to our findings, in Malaysia, 76.1% of medical students had better habitual sleep efficiency which was above 85% 8 . Lack of enough recreational lessons in their annual curriculum and unpredictable school activities as reported in a study in Rwanda might be some of the reasons for this difference 32 . The current study found that both subjective sleep quality and habitual sleep efficiency were significantly different between classes with final-year students significantly presenting the poorest habitual sleep efficiency. These results are in line with previous studies done in India and Brazil which also found these components significantly different among various phases of medical course 35,39 . Moreover, they agree with a prior study conducted in North India which reported that first-year medical students had worse subjective sleep quality compared to other classes 35 . More medical students in the first year 34.6%, significantly experienced a worse subjective sleep quality and this is close to a study in India which found that 35.4% first year medical students reported poor subjective sleep quality 35 . The probable reasons might be that first-year medical student are provided several tasks while they are being reintegrated in a new community which could challenge them in combining several tasks.
Remarkably, the current study found lower use of sleeping medication at 6.6%. When compared to other sleep components, it was even the least impaired. Like our findings, 6.3% and 6% in India and Nepal respectively used sleeping medications 43,44 . Contrarily, higher rates of the usage of sleep medications among medical students were previously reported in Jordan at 21.4% 45 . Similarly, in Saudi Arabia, 24.9% of medical students reported using sleeping medication 46 . In Ethiopia, the use of sleeping medication among medical students was standing at 8.8% 31 . The minimal usage of sleeping medications in the current study is a relief, as sleeping medications have been shown to impair sleep structure and both physical and psychological dependence often follow the use of sleeping medication 47 . That is why even the least usage reported in the current study should be investigated and addressed. www.nature.com/scientificreports/

Strengths and limitations
This study was the first of its kind conducted to the best knowledge of the authors. It was conducted countrywide, and this gives strength to the study as it presents a general picture of the sleep quality among medical students in Rwanda. However, we experienced some limitations: First, though this study used a self-reported scale measuring sleep quality that is psychometric sound as well as fitting well with our context, the participants might give socially desired answers on sensitive questions or not correctly respond some questions as they might not understand 48 . Second, during this study, the education sector was recovering from delays caused by lockdowns of COVID-19, thus medical students had both online and virtual classes that could affect their sleep quality. Third, because this study did not examine the factors that might contribute to poor sleep quality among medical students, more research is needed to examine these factors among medical students in Rwanda.

Conclusion
In overall, the prevalence of poor sleep quality was alarming in medical students with some participants reporting using medication to fall asleep. Most medical students had less than recommended hours of sleep and their habitual sleep efficiency was the most impaired. However, final-year and first-year students experienced the poorest sleep quality compared to other classes. A large number of medical students suffer from mild to severe daytime dysfunctions. Despite overall poor sleep quality, we found lesser use of medications to fall asleep. Based on these findings, intervention methods such as sleep education, behavioural changes, and relaxation techniques are suggested to address the factors that contribute to poor sleep quality. To address this sleep issue, it is also critical that health promotion policies and strategies, particularly those focusing on healthy sleep hygiene, can be implemented. Though factors linked to modern technologies like the use of social media or more time spent on screens are globally known as the main factors leading to poor sleep quality among medical students 11,49 , future studies should consider psychosocial, and environmental factors that contribute to poor sleep quality among medical students, as well as conduct a prospective study to determine the cause-effect relationship of risk factors for poor sleep quality.

Data availability
All relevant data were included in the manuscript. However, data may be shared upon reasonable request and is provided to the corresponding author. www.nature.com/scientificreports/ Publisher's note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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